Upholstered furniture such as sofas, love seats, and chairs are typically constructed with a number of springs of a certain gauge that define a seating firmness. Given a range of height or weight parameters of the consumer, or additional medical or comfort considerations, a sofa of particular seating firmness or pitch (tilt) may be preferred by a given consumer. However, having chosen a piece of upholstered furniture for a particular pattern or design, the consumer may find that the seating firmness and/or pitch does not match his or her preferences. Where such is the case, the seating firmness cannot ordinarily be changed due to the fact that the springs that define the seating firmness and tilt are individually and permanently attached to the frame of the upholstered furniture. Conversely, for the same reasons, a consumer that prefers a particular seating firmness or tilt may be unable to find a pattern or design that matches his or her interior design needs.
It would be entirely possible for a family or a group of users to have a mixed preference for both firm and soft seats. Given the above listed constraints, however, it would not be possible for a family or group of users to have more than one seating firmness or pitch within the same piece of furniture. For example, it would not be possible in a sofa or love seat to have one portion of the seat to be firm and another soft.
From the perspective of the furniture dealer, the necessity of stocking furniture with varying degrees of firmness multiplies the amount of available stock that the dealer must keep on hand, or the dealer must, in the alternative, forego sales to prospective customers that have preferences in seating firmness that are different from what the store has stocked.
For the case of sofas, sofas are constructed to have a permanent coil deck. Sleepers have a mechanism which folds out to become a bed. Because both sofa and sleeper types have their own respective markets, it is necessary for furniture stores to stock both types. Thus, a furniture store may find it necessary to stock sofa and sleeper types in identical upholstered patterns and to stock an adequate variety of different patterns in each of the two types, as well as maintaining stock on pattern-coordinated love seats, chairs, stools, etc. As may be apparent, the stocking of sofas having permanent coil decks and sofas having sleeper mechanisms adds a significant inventorial burden to furniture stores.
Accordingly, a need has existed for a single type upholstered furniture construction that allows the seating firmness and pitch to be readily changed or customized, and, for the case of sofas, to allow for interchangeability of a coil seating module with a sleeper mechanism. Thus, a single sofa may be customized to purchaser or consumer preference for a seating firmness and be comfort pitched. Separate modules may even offer different firmness and/or comfort pitch within the seats of one sofa. The same sofa is interchangeable to a sleeper. Therefore, one floor item for a furniture store offers all of these options. These options are currently only available if the dealer stocks a distinct unit for each customer preference.